Cardiac Effects of Peptidoleukotrienes

Abstract

The leukotrienes are a group of newly identified eicosanoids of the lipoxygenase pathway of arachidonic acid metabolism (Samuelsson, 1981). The peptide-con-taining leukotrienes (LT) (i. e., LTC4, LTD4, and LTE4) are known to possess potent biological properties including bronchoconstriction (Holroyde et al., 1981), enhancement of vascular permeability (Peck et al., 1981), and vasoconstriction (Yokochi et al., 1982). In this regard, it is well documented that leukotrienes C4and D4 are potent coronary constrictors in a number of animal species (Woodman and Dusting, 1983; Terashita et al., 1981). Previous work in our laboratory has shown that the leukotrienes are potent constrictors of isolated perfused cat coronary arteries (Roth and Lefer, 1984). Leukotrienes have also been claimed to exert direct negative inotropic effects on the myocardium (Burke et al., 1982). The purpose of this investigation was to examine the inotropic effects of the leukotrienes in relation to their potent coronary constricting activity and to clarify the relationship between coronary vasoactivity and inotropicity in cardiac preparations isolated from three commonly used mammalian species.